Katie Couric's Notebook: Darkening Gulf

On Saturday, BP declared the "top kill" method a failure after thousands of barrels of heavy mud couldn't plug the well. Now the company is sawing through the leaking pipe, and will then try again to cap it.

It's tempting to hope this time will be different...the oil will stop...and we won't have to wait until August, when BP's two relief wells are expected to be finished.

Six weeks into this catastrophe, as many as 45 million gallons of oil have already spilled, four times as much as in the Exxon Valdez disaster. One recent estimate put fishing and tourism losses at over 4 billion dollars.

For years to come, this will be a case study in crisis management...not only by corporate america but by the government as well. In the meantime, the Gulf keeps getting darker and darker...and so does this story.

That's a page from my notebook.

I'm Katie Couric, CBS News.